<template>
    <div>
        <h1>当前求和为：{{sum}}</h1>
        <select v-model="n">
            <option :value="1">1</option>
            <option :value="2">2</option>
            <option :value="3">3</option>
        </select>
        <button @click="incremnt">+</button>
        <button @click="decrement">-</button>
        <button @click="incrementOdd">当前和为奇数再加</button>
        <button @click="incrementWait">等一等再加</button>
    </div>
</template>

<script>
    export default {
        name: 'Count',
        data(){
            return {
                n: 1, //用户选择的数据
                sum: 0, //当前的和
            }
        },
        methods: {
            incremnt(){
                this.sum += this.n
            },
            decrement(){
                this.sum -= this.n
            },
            incrementOdd(){
                if(this.sum % 2){
                    this.sum += this.n
                }
            },
            incrementWait(){
                setTimeout(() => {
                    this.sum += this.n
                }, 500)
            },
        }
    }
</script>

<style scoped>
    button {
        margin-left: 5px;
    }
</style>